dimanche 17 janvier 2010

Pingvinane and installation of two new OTCs

15 January, Friday

Sunny, mild wind SE. At 9 o’clock, we met with our field guides at the base and at about 10, we went to Pingvinane on 4 skidoos with 2 sledges.

We were a party of 6 people, the 2 field guides (Alain and Sanne) and 4 scientists. In the morning, we broke one of the OTCs, so we took a third one.
After about half an hour driving, we arrived to the Ping01 waypoint, that was marked with 2 bamboos with flags. There, we separated into 2 groups: Elie, Steve and Sanne, Josef, Alain and myself. There are several nunataks in Pingvinane, situated on a straight line. When you see them from far, it looks like a series of pinguins following each other. I guess that this is the reason of their name? But there are really no pinguins here, it is too far from the sea.

At 11:30, we arrived at the 1st Pingvinane. Probably, it was not visited by Annick last year. A small valley at the Northern slope of the nunatak attracted our attention. It seemed to be well protected from dominant SE and E winds. It was well exposed to the sun and there were patches of snow on the slope above. We took 3 OTCs but broke them all!! So, when we tested the construction in Liège, it seemed really good, but the device seems quite fragile at low temperatures. They were also maybe shaken too hardly on the sledge, as the ice can be a bit bumpy. It is quite a problem that we did not expect!
In the deepest part of the valley (eastern corner) and most protected from the winds, we found a black biofilm on the gravel under a patch of snow. The rock surface temperature was +4.5 C, but there was only -1.8 C in the air. For Damien Ertz (lichenologist at the Belgian Botanical Garden), I have collected a red lichen, 2 m to the East in cracks of a big stone. This area could be good for an OTC installation, but the best place is located on a slope and thus, is not suitable for OTC installation, as we need a flat surface.

At the eastern side of a nunatak in a windscoop, under a big stone on the North side, there were big green patches of Prasiola sp (a green algae). In addition, there were many bodies and skeletons of snow petrels that fertilise this area and stimulate the growth of Prasiola. That was already observed in 2007 by Damien, concerning the areas of the Utsteinen nunatak that were situated below the nests of petrels.
Again, we found a nice cryoconite (making a long stream under the ice. 0.5-1 m width). It is located at the entrance to the blue ice field and Alain broke its lid just by tapping with the foot. Indeed, the lid was only 1-3 cm thick, the total depth was 14 cm, and there grew a biofilm above a thick layer of sediments. The temperature inside on the surface of the biofilm +1.1 C. There was not a lot of water, but the sediments and sand were wet.

Then, we visited the 2nd Pingvinane nunatak, located to the North from the 1st. It has relatively small size and doesn't have a well protected area behind. We collected samples on the North-Eastern slope. It is exposed to the wind E-SE, and thus, only the areas between stones are more or less protected. This place was visited by Annick according to Alain, who was here with Karolien and Annick last year. Here I collected a black biofilm on gravel between stones. The weather is sunny, but windy.

We continued with the survey of the 3rd Pingvinane nunatak. It was also visited by Annick last year. They worked on a SW-W slope that is big and relatively flat.

It is protected by a big snow ridge and have long blue ice field behind. Alain’s scooter had crampons to be able to ride on ice, but mine didn't. Alain went first on the ice and managed quite well, but I and Josef started to rotate on ice, then we stopped. Alain came back with sledges and took us. Josef was sitting on a sledge and was moving to the right or left side of a skidoo, when we were turning.
Then, we went to the Northern slope of the nunatak that was not visited by Annick. There were very well protected and flat areas composed of gravel and a lot of sun. Surprisingly, we didn't find any visible biofilm on the surface. There was even a pool of a liquid water (+5.8 C), but no visible living communities! Probably this area is not stable enough for the formation of surface biofilms. However, when we started to dig 3-4 cm below the surface of the gravel, we found a big piece of fine matter. I have collected this sample, as it could be a very fine soil with sand or it could be a former biofilm that was later covered by gravel during snow melting.
Under the gravel (10-20 cm depth) there was ice.
We can add a fourth condition for the formation of a visible biofilm in this area in addition to first three - the substrate must be stable. The possible period of time for active life is not long in Antarctica and if the area is regularly disturbed, biofilms cannot recover.

Then, we started to repair the OTCs. In fact, it was good that we broke one in a morning because we could use its parts for repairing the other 2 OTCs. We went first to take the skidoo that was left behind, in the middle of the ice field. I was sitting on mine and Alain was sitting on his skidoo and was pulling mine with a cord.

After that, we returned to the SW-W slope to install the OTCs there. This area is mostly exposed to the sun during the second half of the day because it is oriented to the W. The temperature of the surface before installation was up
to +12.1 C whereas the T air was -2.4 C. We marked it in Josef’s GPS as a waypoint OTC 3&4. A microsensor for temperature was installed inside OTC3, and a humidity one inside OTC4. An additional microsensor to record the temperature was installed outside the OTCs in the control area. This area is marked with 3 spikes, each side of the control area is about 1 m long. The distance between the OTCs and the control area is between 2.5 and 1.4 m. I collected a black biofilm on the gravel.
At about 17 h, the sky started to become covered with clouds.

We went by skidoos to a waypoint Ping01 and waited there for Elie, Steve and Sanne. They had switched off their radio because it was interfering with the ground penetrating radar. As we did not have any news, at 18 h, Alain and Josef went to see them. When they returned, they told me that the other group was still working and will come back later.

We started to ride and at 19-19.30, we were back at the camp.

The weather is becoming worse and we expect a snow storm in the night. Only after coming back, I realised that we didn't install pancake forms anywhere. We want to use them as passive traps for aerial particules, in the hope that we can find some living material. This type of ‘equipment’ (in fact, used for cooking cakes!), is used by American colleagues in the Mc Murdo Dry Valleys. At the SCAR meeting in 2008, Annick discussed with Marie Sabacka of the lab of John Priscu, who gave some information. Of course, there is probably more transport of aerial matter in the Mc Murdo Dry Valleys, because of the numerous lakes, seasonal rivers, microbial mats… Anyway, we will install them after the storm. It is better, as they probably would become immediately covered with snow.
Cheers, Zorigto

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